1. Technical Field
The present disclosure relates to a modulation device, light emitting device, and light emission system, and in particular to a modulation device used for light communication such as visible light communication.
2. Description of the Related Art
In light emission systems such as an electronic sign including a plurality of light emitting devices capable of light communication such as visible light communication, the plurality of light emitting devices are required to transmit the same identification information (ID) in synchronization. This is because even a light communication reception device located in a region in which light from the plurality of light emitting devices overlaps needs to be able to receive a single ID without failure.
Conventionally, various techniques have been proposed regarding such a light emission system (for example, see Japanese Unexamined Patent Application Publication No. 2013-110599). In Japanese Unexamined Patent Application Publication No. 2013-110599, a plurality of lighting devices are connected to a common visible light communication signal output device, and the plurality of lighting devices receive a single ID from the visible light communication signal output device and emit visible light at the same time. Accordingly, the plurality of lighting devices can transmit the same ID in synchronization via visible light communication.